package com.example.demo.bean;

import com.fasterxml.jackson.core.JsonProcessingException;
import com.fasterxml.jackson.databind.ObjectMapper;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Component;

import javax.websocket.*;
import javax.websocket.server.PathParam;
import javax.websocket.server.ServerEndpoint;
import java.util.Map;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.atomic.AtomicInteger;

@Slf4j
@ServerEndpoint(value = "/test/chatroom/{currentUser}")
@Component
public class ChatroomWebSocket {

    /**
     * 记录当前在线连接数
     */
    private static AtomicInteger onlineCount = new AtomicInteger(0);

    /**
     * 存放所有在线的客户端
     */
    private static Map<String, Session> clients = new ConcurrentHashMap<>();

    /**
     * 连接建立成功调用的方法
     */
    @OnOpen
    public void onOpen(Session session, @PathParam("currentUser") String currentUser) {
        onlineCount.incrementAndGet(); // 在线数加1
        clients.put(currentUser, session);
        log.info("有新连接加入：{}，当前在线人数为：{}", currentUser, onlineCount.get());
        sendMessage("[system]您已上线", session);

//        for (Map.Entry<String, Session> entry : clients.entrySet()) {
//            sendMessage("我宣布个事！", entry.getValue());
//        }
    }

    /**
     * 连接关闭调用的方法
     */
    @OnClose
    public void onClose(Session session) {
        onlineCount.decrementAndGet(); // 在线数减1
        clients.remove(session.getId());
        log.info("有一连接关闭：{}，当前在线人数为：{}", session.getId(), onlineCount.get());
    }

    /**
     * 收到客户端消息后调用的方法
     *
     * @param data 客户端发送过来的消息
     */
    @OnMessage
    public void onMessage(String data, Session session) throws JsonProcessingException {
        log.info("服务端收到客户端[{}]的消息:{}", session.getId(), data);
        ObjectMapper objectMapper = new ObjectMapper();
        ChatMessage chatMessage = objectMapper.readValue(data, ChatMessage.class);
        Session toSession = clients.get(chatMessage.getToUser());
        if (toSession == null) {
            this.sendMessage("对方不在线", session);
        }
        this.sendMessage(chatMessage.getMsg(), toSession);
    }

    @OnError
    public void onError(Session session, Throwable error) {
        log.error("发生错误");
        error.printStackTrace();
    }

    /**
     * 群发消息
     *
     * @param message 消息内容
     */
    private void sendMessage(String message, Session session) {
        log.info("服务端给客户端[{}]发送消息{}", session.getId(), message);
        session.getAsyncRemote().sendText(message);
    }
}
